The long-term objectives of this research project are (1) to determine the effects of three interventions on physical activity and other health outcomes at 12 months post-randomization among 300 sedentary and underactive older adults aged 55 to 80 years, and (2) to determine whether prosocial behavior is a construct that can be successfully implemented within Social Cognitive Theory. Based upon our preliminary study, we have designed a prosocial behavior physical activity intervention that will incorporate opportunities to aid the Second Harvest Food Bank of Northwest North Carolina based upon weekly physical activity. Along with the established benefits associated with physical activity, the